So I’m sure people could work out the generalized implementation of Mark’s suggestion but I thought I’d post it for comments.
I’ve created a generic ParameterNameSpecimenBuilder
based on Mark’s LifeSpanArg
:
public class ParameterNameSpecimenBuilder<T> : ISpecimenBuilder
{
private readonly string name;
private readonly T value;
public ParameterNameSpecimenBuilder(string name, T value)
{
// we don't want a null name but we might want a null value
if (string.IsNullOrWhiteSpace(name))
{
throw new ArgumentNullException("name");
}
this.name = name;
this.value = value;
}
public object Create(object request, ISpecimenContext context)
{
var pi = request as ParameterInfo;
if (pi == null)
{
return new NoSpecimen(request);
}
if (pi.ParameterType != typeof(T) ||
!string.Equals(
pi.Name,
this.name,
StringComparison.CurrentCultureIgnoreCase))
{
return new NoSpecimen(request);
}
return this.value;
}
}
I’ve then defined a generic FreezeByName
extension method on IFixture
which sets the customization:
public static class FreezeByNameExtension
{
public static void FreezeByName<T>(this IFixture fixture, string name, T value)
{
fixture.Customizations.Add(new ParameterNameSpecimenBuilder<T>(name, value));
}
}
The following test will now pass:
[TestMethod]
public void FreezeByName_Sets_Value1_And_Value2_Independently()
{
//// Arrange
IFixture arrangeFixture = new Fixture();
string myValue1 = arrangeFixture.Create<string>();
string myValue2 = arrangeFixture.Create<string>();
IFixture sutFixture = new Fixture();
sutFixture.FreezeByName("value1", myValue1);
sutFixture.FreezeByName("value2", myValue2);
//// Act
TestClass<string> result = sutFixture.Create<TestClass<string>>();
//// Assert
Assert.AreEqual(myValue1, result.Value1);
Assert.AreEqual(myValue2, result.Value2);
}
public class TestClass<T>
{
public TestClass(T value1, T value2)
{
this.Value1 = value1;
this.Value2 = value2;
}
public T Value1 { get; private set; }
public T Value2 { get; private set; }
}